Recent advances in CD8 regulatory T cell research.

Various subgroups of CD8 T lymphocytes do not only demonstrate cytotoxic effects, but also serve important regulatory roles in the body's immune response. In particular, CD8 regulatory T cells (CD8 Tregs), which possess important immunosuppressive functions, are able to effectively block the overreacting immune response and maintain the body's immune homeostasis. In recent years, studies have identified a small set of special CD8 Tregs that can recognize major histocompatibility complex class Ib molecules, more specifically Qa-1 in mice and HLA-E in humans, and target the self-reactive CD4 T ce lls. These findings have generated broad implications in the scientific community and attracted general interest to CD8 Tregs. The present study reviews the recent research progress on CD8 Tregs, including their origin, functional classification, molecular markers and underlying mechanisms of action.